Automatic adjuster for eccentric shafts.



APPLICATION FILED DEC. 13. I915- Patented Apr. 24, 1917.

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GERALD DE COURGY MAY, OF WASHINGTON, DISTRICT OF COLUMBIA.

AUTOMATIC ADJUSTER FOR ECCIENTRIC SHAFTS.

Application filed. December 13, 1915.

To all whom it may concern:

Be it known that l, GERALD DE Connor MAY, a citizen of the UnitedStates, residing at Washington, District of Columbia, have inventedcertain new and useful Improvements in Automatic Adjusters for EccentricShafts, of which the following is a specification.

This invention relates to an adjustment for shafts having eccentricportions, and is especially adapted for use in connection with rotarypumps.

For purposes of illustration 1 have shown and described the invention asapplied to a pump of thehlay-Nelson type, and especially to that form ofpump shown in the patent granted to me Oct. 12, 1915, No. 1,156,700.

Applied to a pump of this type the object of the invention is toovercome the difficulty of obtaining and maintaining the best possibleadjustment of clearance between the rings of the impeller and the fixedwalls of the pump body.

The invention consists of the novel features of construction hereinafterdescribed, pointed out in the claims, and shown in the accompanyingdrawings, in which Figure 1 is a side sectional elevation showing theinvention applied to a pump of the type mentioned. A

Fig. 2 is an enlarged section on the line 22 of Fig. 1.

Fig. 3 is a longitudinal section through the shaft and bushing, a rodbeing in elevation.

Fig. 4 is a plan of the outer end of the shaft with my invention appliedthereto.

Fig. 5 is a side elevation of the outer end of the shaft.

Fig. 6 is a cross section through the bushing and squared portion of arod.

Fig. 7 is a perspective view of a shaft plate.

F 8 is an end view of the bushing.

Fig. 9 is a plan view of a modification.

Fig. 10 is a side elevation of Fig. 9.

Fig. 11 is an end elevation of Fig. 9.

In these drawings 1 represents an oil casing, 2- the top of a pump ofthe May-Nelson type, 3 the impeller, having-the rings 3 and 4: the bodyof the pump carrying the usual stationary walls. A shaft 5 having aneccentric portion 6 operates the impeller. All of these parts are shownand fully described in the patent above referred to, and are i1lus*Specification of Letters Patent.

Patented Apr. 2%, 1917,, Serial No. 66,485.

trated in the accompanying drawings to bring out more clearly theadvantages of the present invention.

The shaft 5 is provided with a longitudinal bore 8 on the aXialline ofthe eccentric portion 6 and through said bore passes loosely a rod 7.This rod terminates at its inner end in a squared pin 9.

arm 13 is set in the outer end of the shaft.

A suitable collar 14 is adjustably secured, as by a set screw, on theprojecting portion of the rod. A bolt 15' connects the two arms, andcarries a spring 16 the ends of which bear on the arms, and said springexerts pressure on the rod 7, and through it on the bushing 10, at aright angle to the axis of the rod and bushing.

In other forms of pumps or shaft mountings I find it desirable to modifythis construction somewhat, placing on the outer end of the shaft a yoke17, securing a sleeve 18 on the rod 7, with an arm 19, and a bolt 20 iscarried by the yoke and the arm and carries a spring 21.

In both forms the principle and results obtained are the same.

Suitable nuts, pins, etc., are employed where necessary.

The nut 22 carried by the bolt may be used as a stop in certain cases,and the spring pressure can be increased or decreased by adjustment ofthe sleeve or collar 14, and arm 15, if the nut 22 should be at itslimit of travel.

111 pumps of this type the maximum possible eccentricity is limited bycontact of the impeller with the walls of the pump body, or by the nut22 if used as a stop.

By tests made on vacuum pumps it has been found that by means of thisdevice the spring compensates for any variations in machine work on thepump, and produces at all times a minimum clearance between the impellerand the pump body, producing a better and steadier vacuum than it hasbeen possible to obtain with a fixed adjustment,

no matter what means were employed for obtaining fine variations of theposition of the eccentric bushing. This has been proven by testing bothmethods on the same pump.

This device also prevents breakage or damage of parts of the pump shouldforeign matter enter therein, by permitting the necessai'y increasedclearance between the working parts, the rings and the walls, until suchmatter has been ejected, and such action is automatic. Expansion andcontraction due to temperature changes are also automatically taken careof by this device.

What I claim is 1. The combination with a pump of the kind describedcomprising a shaft having an eccentric portion on its inner end, abushing thereon, and an impeller actuated by said bushing, said shaftand eccentric portion having a longitudinal bore therethrough, of a rodin said bore and extending therefrom at each end, an arm carried by theouter end of the rod and at an angle thereto, and a spring supportedfrom said shaft and bearing on said arm.

2. The combination with a pump of the type described comprising a shafthaving an eccentric portion at its inner end and a longitudinal borepassing through said shaft and eccentric portion, a bushing on saideccentric portion, and an impeller engaging said bushing, of a rodpassing loosely through the said bore and projecting therefrom, theouter end of the shaft being recessed, a plate fitting in said recessand having a projecting arm, an arm secured to said rod, and a springarranged between and bearing on said arms.

In testimony whereof I aflix my signature in the presence of twowitnesses.

GERALD DE COURCY MAY.

Witnesses:

HENRY MAY, MICHAEL KILEGLANE, Jr.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

